A Suffolk headteacher has criticised an Ofsted report as making “sweeping and inaccurate” generalisations about his school.

Stowmarket High School was given a “requires improvement” grade in its latest report by Ofsted inspectors.

The school, which includes a sixth-form and has more than 850 students, was criticised in the report for its teaching with children falling below national standards in some subjects.

Inspectors in the previous two reports in 2009 and 2011 also gave the school a level three score, previously known as “satisfactory”.

Headteacher Keith Penn said although he had agreed with parts of the report, the inspectors’ findings had been “disappointing”.

“The short timescale (of the inspection) does not allow a great deal of time for detailed investigation of other areas of school life which are an important part of the life of a school and it is unfortunate that inspectors – in this school and elsewhere - feel able to make rather sweeping and inaccurate generalisations about other aspects of the school which are clearly based on little more than a single conversation or throwaway comment,” Mr Penn said.

He praised the latest GCSE results which had put the school “firmly back” on a “positive gradient” and said A-level results had been “excellent”.

But in all four report areas, including achievement of pupils and leadership and management, the school was given a “requires improvement” mark. No-one from Ofsted was available to comment.